Kate Middleton Is Adorable -- and Can't Stop Smiling -- With William and Harry at Kids' Charity Event

The 33-year-old Duchess of Cambridge was beautiful as ever during a meeting of the Charities Forum at BAFTA in London on Monday, but looked especially ecstatic to be around children and Princes William and Harry.

The three royals joined children from the various charities they support to celebrate the premiere of the new animated film, Shaun the Sheep: The Farmer's Llamas. The fun activities included "welly wanging," which involves throwing a wellington boot as far as possible.

And the mother of two didn't let her stylish, space print Tabitha Webb dress and black high heels keep her from participating. Check out Kate's throwing arm!

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And have you ever seen her this happy?!

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Naturally, 31-year-old Prince Harry and 33-year-old Prince William had a great time as well, bonding with the adorable children.

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Getty Images

Earlier this month, Prince William opened up about his late mother, Princess Diana, when talking about another important charity to him -- Child Bereavement U.K., which Diana helped launch in 1994.

"My mother was determined to help those in need and she would have been immensely proud -- as I am -- of all that Child Bereavement U.K. has achieved these last 21 years," William said of the charity, which supports families and educates professionals when a baby or child dies, or is dying.

William, of course, lost his mother in a car accident when he was only 15 years old.

"What my mother recognized back then -- and what I understand now -- is that grief is the most painful experience that any child or parent can endure," he added. "As a father to two young children myself, I now appreciate it all the more."